1. Field of the Invention
The present invention relates to an image processing method and an image processing apparatus, and, more particularly to a digital multifunction peripheral (MFP) that includes functions of a copying machine, a facsimile, a printer, a scanner etc., an image processing apparatus of a color facsimile, a color printer, a color hardcopy etc., an image processing apparatus related to digital image data and that is suitable for a color-print software application operated on a personal computer, an image processing method, and system configuration thereof.
2. Description of the Related Art
With the development of reading units that use a line sensor made of a charge-coupled device (CCD) photoelectric conversion element and toner-writing devices that use laser irradiation, digital copying machines came into existence that produce copies in digital image data by using an analog copying machine.
Since the digital copying machine came into existence, compatibility with other devices that handle the digital image data has improved. In addition to serving as a copying machine, the digital copying machine combines various functions such as a facsimile function, a print function, and a scanner function and is known as a digital multifunction peripheral (MFP) than merely a digital copying machine.
Along with increase in memory and decrease in cost of a hard disk drive (HDD), increase in speed and use of communication techniques such as a network, enhanced throughput of a central processing unit (CPU), advancement of MFP-related techniques such as digital image data-related techniques (compression techniques etc.), the number of functions included in the MFPs has increased.
However, usage of the MFP is also diversified. For example, a pair of compact MFPs is placed next to a personal computer (PC) and an operator can easily use the functions of the copying machine, the facsimile, the printer, and the scanner that are included in the MFPs. Medium-sized MFPs also exist that are shared by a plurality of users in various departments or sections. The medium-sized MFPs have a certain degree of productivity and that include the functions of sorting, punching, stapling etc. Large-size MFPs that have high productivity, high quality, and multiple functions are used in departments that provide centralized copying-related services for an entire company, or in companies engaged in copying-related services.
Thus, there are various types of MFPs from compact MFPs to large-size MFPs. The MFPs include functions that can be shared by various classes and also include the functions that are strongly demanded for each class. For example, the large-size MFPs that can perform finishing work such as punching, stapling, and folding after paper plotting, and that can simultaneously perform copying and electronic filing are in demand. Further, the compact MFPs with enhanced internet fax and PC-fax etc., high-quality image printing on exclusive papers for personal use etc. are in demand.
Thus, various new functions are provided, and it is desirable to provide and integrate new functions also in the MFPs that handle digital image data, which is a part of the digital data. However, in a vast MFP market, conventionally a system was developed and marketed that had functions dedicated to each class.
The importance of information value in business is already accepted. The information should be conveyed faster, more accurately, and more authentically, and also in a simplified and effective manner. Along with increase in speed and use of communication techniques, increase in memory, decrease in cost and size of storage devices, and increase in PC performance, new functions are provided that effectively handle the digital data. It is desirable to provide and integrate new functions also in the MFPs that handle the digital image data, which is a part of the digital data.
If development and integration of new functions in the MFPs continues, a following case can be assumed. In a digital color MFP equipped with various color image input-output devices, for color images imported using a scanner and color documents created using an application on the PC, color correction and color processing are executed according to colors detected. Further, a printout is taken after converting to printer control signals (cyan, magenta, yellow, and black (CMYK)) and image distribution is done via an external interface (I/F) after converting to standard signals such as standard red, green, and blue (sRGB).
Known technologies related to the present invention are disclosed in the following disclosures, namely, Japanese Patent Nos. 2721174 and 3713352, and Japanese Patent Application Laid-open No. 2007-88783.
As described in Japanese Patent Nos. 2721174 and 3713352, a color domain that includes colors indicated by image signals is determined, predetermined parameters are selected depending on the determined domain, and the image signals are processed based on the selected parameters. Due to this, color correction, color processing, color adjustment etc. can be flexibly carried out. However, when handling several colors, various problems regarding color correction are encountered.
For example, as described in Japanese Patent No. 3713352, hues are derived by converting from red, green, and blue (RGB) image signals into two-dimensional image signals that represent a color plane. However, even though hues are detected for the RGB signals imported by using the scanner, and for example, standard display RGB signals such as sRGB handled on the PC, the same color domain is determined, and color correction and color processing are executed, characteristics of the RGB signals differ. Therefore, conversion results requested for both input images cannot be obtained.
As described in Japanese Patent Application Laid-open No. 2007-88783, even when characteristics of the RGB signals that are handled internally are matched, as shown in FIG. 8, a definition (chromaticity point) of basic hues such as cyan (C), magenta (M), and green (G) differs in paper printouts (reflection copy) and in the colors on display (light-source colors). Therefore, even though the common RGB signals are converted into the two-dimensional image signals, the colors are derived, and color correction and color processing are executed, the conversion results requested for the images imported from the scanner and the images created on the PC cannot be obtained.